Can you put a Krell in an apartment?

Boulder? Yeah,  I will check them out. They run cooler than Krells. Might be more musical. Plus if they break, Colorado is a lot closer to me than Connecticut. I see a few on market. Harley's and high end Audio, a great combination 
 

I would just make sure the plug has 12gage wire.  If it is 14gage which I've seen before, it will be like trying to suck a bowling ball through a garden hose, electrical wise.  Of course the a generator/inverter on the balcony may be an option.

I would not be that comfortable buying a 30-year old solid state amp.  Many of the components, like the output transistors, may be hard to replace if they go bad.  Tube gear is quite different in that most of them can be relatively easily serviced and stuff that is 60-70 years old don't give me much concern.  

If you are now considering alternatives to the Krell, it would help to know about the rest of your system, that is, if sound quality is of some importance.  

I don't quite understand going to extremes to fit in one piece of gear instead of looking for something appropriate to the system and the venue.  A small apartment should mean looking for suitable speakers and then electronics that work well with the speakers.  I cannot imagine why some high-powered behemoth is suitable, even if the speakers are notoriously inefficient or need some juice to come alive.

Boulder 850s ( now discontinued) might be a great "apt. amp'   Small 40 lb boxes, run cool, I think they sound great with proper preamp .

They are rated at 200 w/ch but fight above their weight.  Some people find them to dry but I prefer the power amp remain neutral and adjust the tone of the system via, front end componets and cabling.

Look around. They pop up used now and then

I’m sensing you going against all instincts here and getting the amp... I’ve done that before too. Makes for a longer road (and $$) than expected to get where you're ultimately meant to be.